The utilization of ultrasonic gas leak detectors is increasing in industrial applications such as oil and gas and petrochemical industries for the detection of leaks of pressurized combustible and toxic gases. Rather than relying on the gas reaching the sensor element, ultrasonic gas leak detectors detect a leak through the ultrasound produced by the escaping gas, for mass flow rates ranging from a fraction of a gram per second for small leaks to over 0.1 kg/sec for larger leaks. The ultrasonic gas leak detector monitors the airborne sound pressure level (SPL), measured in decibels (dB), generated by the pressurized gas leak: the detection range scales with the sound pressure level (SPL) produced by the leaks.
One of the principal advantages of ultrasonic gas leak detectors is that leaks can be simulated, using inert, safe gases, providing a method for system verification that is uncommon among other type of gas sensors. Using an inert gas such as helium or nitrogen as a proxy, a technician can produce leaks at a controlled leak rate through an orifice of known size and shape without creating a hazardous situation. Such simulation is useful for determining adequate coverage for minor leaks that should be caught before the hazard escalates into a more severe incident.
While simulation using inert gases is an established practice for the setup and commissioning of ultrasonic gas leak detectors, there as yet, does not exist any means for testing system functionality of the installed gas detectors on a routine, inexpensive and convenient basis. The result is a capability gap in being able to provide a remote gas check or “bump test” to ensure system readiness and functional safety. It is very cumbersome and costly to carry bottles of pressurized inert gas around a plant environment comprising pipes, scaffolding and stairs. Logistic issues are also involved in the timely delivery of gas bottles and appropriate gas regulators, and in the transportation of the heavy gas bottles to the test sites.